Update: it appears Kalcor has sneaked in a update to the actor system in with some simple health functions, along with IsValidActor. I have updated the tutorial with them but after checking the R3 include they seem to be missing, so I guess they're only present in the official release.

I have to disagree with "I make actor's walk around?".
Because I managed to sync actors between players and make them walk around, they don't exists in areas where there are no players, but there is always actor near player, spawned actor have only one player to be synced with until that player leave certain radius of actor